#include <fstream>
#include <iostream>
#include <algorithm>

using namespace std;

ifstream f ("tribute.in");
ofstream g ("tribute.out");

const int NMAX = 5e4;
int x[NMAX+1], y[NMAX+1];
int n;

int suma_distante(int v[], int lung, int n){
    
    int st = 1;
    int dr = n;
    int suma = 0;
    sort(v+1, v+n+1);
   
    while(st<dr and v[dr] - v[st]>lung)
        suma+=v[dr] - v[st]-lung, st++, dr--;
    return suma;
}

int main()
{
    int n;
    f>>n;
    int d1, d2;
    f>>d1>>d2;
    for(int i=1; i<=n; i++)
        f>>x[i]>>y[i];
    int S=0;
    
    S+=suma_distante(x, d1, n);
    S+=suma_distante(y, d2, n);
    g<<S;
    

    return 0;
}